What seems at first to be a very straightforward “paint-by-numbers” installment in the sitterverse (yawn: the sitters hold a day camp for some of their charges) turns out to be an intricate, surprising, and genuinely frightening origin story for Mary Anne Spier herself. As the boys pick apart the strands in this delicate tapestry woven by Ann M. Martin and the great Nola Thacker, they begin to wonder whether they’ve uncovered something that none of us were meant to know. Because this one goes all the way down, Baby Nation. All the way. Down. Some completely unwarranted and baseless slander of the fine city of Cleveland in this episode, which is still nowhere near as offensive as how many total minutes it takes Jack to get through one two-clause sentence about the B-plot of this book. Put your tinfoil hats on for this one, Baby Nation, because you’re gonna need ‘em! Music credits: “Silly Fun,” by Robert Austin “Lavender Town,” by Myuuji “Dead Silence,” by Myuuji “Love Potion,” by Fasol Prod “Link,” by Jim…